Many years ago I was walking the streets of Toronto and I herd incredible music. I spend almost and hour listening to incredible group called Puente del Diablo and ended buying a CD (http://www.puentedeldiablo.com/).
Probably you had similar experience somewhere else in the world.
The project Playing For Change was born in 2002 and unites mostly street musicians. There are many songs and you can find them on YouTube. I put together only 3- Guantanamera, La Bamba and Clandestino (Manu Chau).
Some of the guys came together to perform under PFC Band (Playing for change). Even the most successful musicians started on the street.